Casaubon's Book

Who or What Got the Glyptodons?

i-a8ef0aff516fcaf3040cdb5170f341a3-Glyptodon_(Riha2000)-thumb-400x306-49227.jpg

Ok, part of this is just that I really like the word “Glyptodon” and am trying to find more uses for it ;-). But there is a point here, I’m pretty sure.

A while back I was teaching a class, and the gentleman teaching before me, an Algonquin Native Descendent, who was talking about the history of the ways that waterways in the Northern US had impacted patterns of settlement and development, became quite passionate at the sight of Eric’s t-shirt, which had an mastodon on it. The gentleman launched into a staunch defense of his ancestors, who for a long time were typically considered to be the main culprits in the extinction of the North American mega-fauna, including the Mastodons and Mammoths.

The gentleman argued that his people were being maligned by scholars who have had insufficiently credited climate factors in the extinction of the animals, and claimed that his ancestors were not guilty. Since we’d expressed no opinion on the subject, we were a little surprised to see so passionate a defense, but his observation was that something very critical hinges on this question – and I think he’s right. If historically speaking there are few, or no societies in which humans have lived without basically destroying the creatures and environment around them, we can begin to take from that the idea that humans are inevitably destructive. Indeed, our history seems to support this idea – while new archaeological evidence suggests we were interbreeding with Neandertals, it also suggests that one of our early projects may have been the genocide of the other upright folks like us.

The gentleman in question argued quite forcefully, however, that while North American native people’s were hardly without impact – among other things, they heavily managed forests, rivers and prairies – that fundamentally their impact was much lower than is implied by the attribution of the megafauna extinctions to their credit. If that’s true, he argues, than we should begin to attribute the inability of humans to live sustainably less to an innate human-ness and more to particular types of human habitation and relationshp to their world.

Thus, I found it interesting to read a new study, published in _Evolution_ that suggests in fact that climate change really was a (it would be overstating things to say “the” – it isn’t clear that the gentleman’s ancestors are fully off the hook) primary driver in the extinction of the megafauna. Using this approach, the study’s authors suggest:

The study shows that climate change had a global influence over extinctions throughout the late quaternary, but the level of extinction seems to be related to each continent’s footprint of climate change. When comparing continents it can then be seen that in Africa, where the climate changed to a relatively lesser extent there were fewer extinctions. However, in North America, more species suffered extinction, as reflected by a greater degree of climate change.

A key piece of evidence in the humans versus climate debate is the size of the extinct mammals. It has always been assumed that humans mainly impacted on populations of large mammals, while if climate change played the key role there should be evidence of large impacts on small mammals as well as the larger animals.

The team’s results show that continents which suffered larger climate change impacts suffered larger extinctions of small mammals and viceversa, further strengthening the idea that climate change was a key factor in controlling past extinctions on a global scale.

This research has important implications for the current study of climate change, not only in revealing the role of the climate in causing extinction in mammals, but also by demonstrating how the effect will be different across regions and continents

I personally don’t really have a dog in this hunt – my ancestors both lived on the North American continent and did or did not eat the giant sloths, and lived in Europe and helped exterminate my other ancestors. My own genome is by no means straightforward enough to make it worth taking sides. Moreover, I’m not sure that we can have sufficient certainty on this subject to be able to make a case for a sustainable human history – or not. But if we could, wouldn’t that be interesting?

Sharon

Comments

  1. #1 TTT
    May 18, 2010

    Your Algonquin friend would have us believe that the end of the ice age was delayed in New Zealand and Madagascar until less than 1,000 years ago, which is when all their megafauna died out. Presumably the first human colonists hopped off their canoes and found themselves surrounded by the dead bodies of all the large native animals–still warm to the touch!

    It’s especially puzzling how climate change would have been specific enough to eradicate the populations of Steller’s Sea Cows that bred on the shorelines of the main North American landmass but spared those that dwelt by tiny islands in the Bering Strait–even when the latitude and climate of both populations was exactly the same.

    I’m a bit offended at his offense, to be honest. Implicit in the Pleistocene Overkill theory is that EVERYBODY was doing it: Europeans with their mammoths and woolly rhinos, Maori with the moas, Aborigines with the giant kangaroos and mainland thylacines, and, yes, the ancestors of today’s native North and South Americans with the mastodons and ground sloths. The idea that one group of people should be exempt from this seems to me just a sad attempt at clinging to the myth of the “noble savage.” There aren’t many ways for pre-technological people to hunt large land animals, and there sure aren’t many ways to introduce new hunting pressures and diseases to populations of large slow-breeding animals without killing them off.

    It’s also worth pointing out that prehistoric climate change is by no means mutually exclusive with prehistoric human pressures. Tim Flannery in “The Future Eaters” clearly illustrated how the early Aboriginal use of fire accelerated and magnified the drying out of Australia and helped push a lot of the megafauna over the edge. A great deal of the desert rim of the Mediterranean is a human invention.

  2. #2 Alan
    May 18, 2010

    One point I have not heard discussed in the literature on the mass extinctions in the Americas is that humans were not the only Old World species to cross the Bering land bridge in the not very distant past. As I understand it, both the American Black Bear, and the Grizzly, are descended from pretty recent immigrants, and I believe Moose of the modern form are also of Eurasian origin. I am not sure about all the species, but personally I suspect the demise of Tremarctine bears in North America may have more to do with these new arrivals (possibly via diseases they carried) rather than humans.

  3. #3 Paul S.
    May 18, 2010

    The team’s results show that continents which suffered larger climate change impacts suffered larger extinctions of small mammals and viceversa, further strengthening the idea that climate change was a key factor in controlling past extinctions on a global scale.

    As far as I know, North America and Europe and northern Asia suffered the largest climate changes at the end of the last ice age, but most of the mammals that became extinct on those continents werelarge mammals, not small ones. On the other hand, it seems likely that humans played some role, because many of the extinctions seem to have happened shortly after the first humans arrived. In addition, there appears to have been a wave of extinctions of larger animals shortly after human arrival in other parts of the world (such as Australia and much later New Zealand) that were not as heavily affected by the ice age climate shifts.

  4. #4 darwinsdog
    May 18, 2010

    Most of the Native Americans I know would be proud of the hunting prowess of their ancestors, that they managed to kill off all those big crits. Of course, the Navajos & Apaches I’m acquainted with still speak their own languages.

    Look, all this has been gone over exhaustively decades ago. We understand orbital forcing, we know the periods & amplitudes of the Milankovitch cycles and how they interact to potentiate or cancel one another. We understand the dynamics of the Pleistocene glaciations and their time scales. The thing that marks the end of the Pleistocene & beginning of the Holocene is not climate change but the diaspora of humans across the globe. Naive faunas were heavily impacted by the sudden advent of these technologically sophisticated hunting societies. This was the time when Anthropogenic Mass Extinction, which began in Africa, really picked up steam. Glyptodonts hadn’t coevolved with humans or other apes. So-called ‘Paleoindians’ probably could just knock them in the head with a rock and thereby provide their families with a week’s supply of meat. There’s really no argument anymore about the human etiology of the demise of the American, Australian and island faunas. Yes, climate was changing at the end of the Pleistocene but not so rapidly that natural selection could not keep pace. Earlier glacial stadia were not accompanied by mass extinction events. Humans were the culprits but are not to “blame” for it. Our ancestors were just doing what hungry killer apes do: setting fires & killing off crits.

  5. #5 darwinsdog
    May 18, 2010

    A couple of other things:

    I have long contended that humans and neandertals were separate species that either did not interbreed at all or that produced infertile hybrid offspring when they did so. To my mind, all the evidence supported this conclusion. The new evidence to the contrary is not archaeological but genetic. The neandertal genome has been sequenced and come to find out, humans not of recent African origin share some 1 to 5% of our genes with neandertals, indicating that interbreeding & gene flow did indeed occur following the African exodus of modern humans. In fact, if there are about 5 billion humans not of recent African origin extant, and we share 1% of our genes with neandertals, from the genetical point of view this is the same as saying that 50 million full-blooded neandertals exist! I was wrong about this and proud to admit it now that the evidence has come in.

    During times of mass extinction animals of large body size, both in absolute terms and relative to that of the mean size of their clades, are especially vulnerable. This is just about the one constant feature of mass extinction episodes. It seems to be true of all past episodes, whether of unknown or of bolide impact etiology. It also appears to be true of Anthropogenic Mass Extinction. The reason is probably complex but may be primarily a function of small population sizes & long generation times in large animals. Because large animals virtually always go extinct during times of mass extinction, I don’t expect any mammals much larger than a rat or squirrel to survive AME.

  6. #6 Glenn
    May 18, 2010

    Methinks the Algonquin gentleman doth protest too much. Get over it. I’ll cop to my ancestors commiting genocide on his ancestors. But all our ancestors killed and ate large game wherever we went.

    Glenn

  7. #7 Robin Datta
    May 18, 2010

    If Homo sapiens sapiens does carry Homo sapiens neanderthalis genes, then the Neanderthals didn’t quite go extinct.

    Colder climates tend to select for larger homeotherms as the surface area (for caloric flux) squares with increase in dimension while the volume (caloric reservoir) cubes. So an Ice Age should have preserved some woolly mammoths.

  8. #8 darwinsdog
    May 18, 2010

    If Homo sapiens sapiens does carry Homo sapiens neanderthalis genes, then the Neanderthals didn’t quite go extinct.

    That’s right. In fact, since there’s the functional equivalent of 50 million neandertals walking around right now, they’re doing better than ever, since it’s highly unlikely that anywhere near 50 million actual neandertals ever lived at one time.

    So an Ice Age should have preserved some woolly mammoths.

    The thing is that mammoths and other large animals didn’t go extinct during the previous interglacial – the Eemian – even tho sea level was higher and temperatures warmer than today. They didn’t go extinct because ~120K yrs bp there were no modern humans outside of Africa to kill them off.

  9. #9 Brad K.
    May 18, 2010

    I am not sure I care about whether the mastodons were hunted, or over hunted.

    I recall not that long ago that the American Bison used to be somewhat numerous, until modern, European-descent people chose to shoot up the herds for a few pelts. Not much sustaining went on in the couple of years it took to mostly clear the Great Plains.

    That is one part of “extinctions” that rings really loudly in my mind.

  10. #10 Greenpa
    May 19, 2010

    Ah, those wonderful all-night bull sessions, sophomore year! And here we have so much latitude for unsupported suppositions! :-)

    Also; bear in mind, interbreeding and genocide typically go together; far from being mutually exclusive.

  11. #11 Nomen Nescio
    May 19, 2010

    In fact, since there’s the functional equivalent of 50 million neandertals walking around right now

    well, that’s assuming that at least one copy of every gene/allele that made neandertals uniquely neandertal managed to cross over and survive until today. that may be a debatable assumption, although it wouldn’t surprise me.

    i don’t know much about paleontology, but i’ve heard it claimed that every one of the gross anatomical traits neandertals displayed can be found also in at least some modern humans, it’s just that no single modern human displays them all. i’m a bit doubtful about this myself, but hey, i’ve been wrong before.

  12. #12 Mike Cagle
    May 19, 2010

    It’s an interesting question. I’m sure no expert on that subject, but I have to say I’m skeptical of your Algonquin acquaintance. Tim Flannery discusses this in his book, The Eternal Frontier: An Ecological History of North America and Its Peoples. He points out that other periods of similar climate change in North America, previous to the arrival of humans, didn’t result in similar fast mass extinctions. I recommend this book – it’s really interesting.
    Your friend is deciding an empirical question by coming to a pre-determined ideological conclusion. He probably thinks the Anasazi culture in the southwest couldn’t possibly have disappeared due to overexploiting their resources. That’s another question where some people reason from ideology. Their basic idea is that Native Americans are so spiritually/magically attuned to Mother Nature (and so noble, honorable and innocent) that they just wouldn’t do that! Which strikes me as silly and romantic. Seems more likely to me that Native Americans, like Europeans (and all human groups), are/were opportunistic exploiters of resources, making things up as they go along, doing their best with what they know, and unable to see a long view past two or three lifetimes at the most. Why should they be any different? They are humans like us. To the extent Europeans have been more destructive of nature, it’s mainly because they had more effective technology, not because they are stupider, more evil, or more shortsighted.

  13. #13 Ewan R
    May 19, 2010

    well, that’s assuming that at least one copy of every gene/allele that made neandertals uniquely neandertal managed to cross over and survive until today. that may be a debatable assumption, although it wouldn’t surprise me.

    As far as I recall the study found somewhere in the region of 100 genes which were uniquely human (sapiens sapiens) so the assumption falls flat in that regard.

  14. #14 Greenpa
    May 19, 2010

    Mike: “Seems more likely to me that Native Americans, like Europeans (and all human groups), …unable to see a long view past two or three lifetimes at the most. ”

    That particular point is not likely valid. Pretty trustworthy research among Pacific peoples tends to corroborate their accurate memories of their history and genealogies for many generations back- often 20 or 30; or more.

    Remember, with no TV or TIVO, they just had to sit around the fire and tell stories. :-)

  15. #15 Greenpa
    May 19, 2010

    Ok, this is weird. Yesterday I posted a link to this video on TAE; for very different reasons.

    http://www.youtube.com/watch?v=kjukpfyasxk&feature=related

    If you want to see some authentic primal hunting skills; wait for the latter part of the video, and watch bison being hunted on foot. The images run fast, so be prepared to run it back and look again.

    It’s very sophisticated (the hunting).

    The video quality is poor, but useful; audio is great. The artist is Jack Gladstone; Blackfeet story-teller/troubadour.

  16. #16 Glenn
    May 19, 2010

    IIRC the Euro-American Buffalo hunts were specifically part of a strategy to starve the Plains Natives so they became more tractable, either by dying off, or being willing to move onto the “spacious” reservations. Selling the pelts at a profit was just frosting on the cake. The desired results being security of railroads and telegraphs, and the ability to privatize a public resource by running european descended domestic cattle on the plains.

    Glenn

  17. #17 darwinsdog
    May 19, 2010

    #12:

    He probably thinks the Anasazi culture in the southwest couldn’t possibly have disappeared due to overexploiting their resources.

    “Anasazi” is a corruption of the Navajo term Anaa’i’ sani which means “enemies, the ancient ones.” There were several different cultural groups lumped under the term “Anasazi” and they didn’t go extinct, they were the ancestors of the Hopi, Zuni, and Rio Grande Puebloan peoples. The great cliff dwellings & surface site pueblos on the Colorado Plateau were abandoned upon the advent of Na-Dene speaking peoples, the ancestors of the contemporary Navajo & Apache. When these sub-arctic big game hunting cultures wandered south only a few centuries prior to Spanish colonization, they found the Puebloan peoples easy pickings. It was warfare & cultural conflict that led to the abandonment of Mesa Verde, Chaco Canyon, etc., plain & simple. Climate change, resource over-exploitation & other environmental stressors had little or nothing to do with it.

    #16:

    IIRC the Euro-American Buffalo hunts were specifically part of a strategy to starve the Plains Natives…

    Yup, Glenn. In fact, the US army would issue ammunition to anyone who promised to kill Bison with it. Seldom were even the hides or tongues taken.

  18. #18 Sharon Astyk
    May 19, 2010

    Glyptodon. Glyptodon. Glyptodon. ;-)

    My readership is just awesome – you folks make interesting hay out of everything!

    Sharon

  19. #19 Ed Straker
    May 19, 2010

    I understand the subtext of whether or not the anarcho-primitivist theory of civilization representing us jumping the sustainability shark holds up or is just a “noble savage” myth, but these sorts of debates all seem to devolve into a pissing contest over ancestral guilt/virtue. Let’s go iterate through the sins of one ethnic group vs. another as we compare score-counts and see who holds less collective guilt. It’s all rather pointless.

  20. #20 Greenpa
    May 19, 2010

    Ed – well sure! Although my buddies the Altarean anthropologists love the insights they get into the various limitations in intelligentsial thought processes. :-)

  21. #21 Jason
    May 19, 2010

    Greenpa: “That particular point is not likely valid. Pretty trustworthy research among Pacific peoples tends to corroborate their accurate memories of their history and genealogies for many generations back- often 20 or 30; or more.”

    I think Mike was referring to the ability to see the long view more than a generation or two ahead.

    I’m not questioning native american oral history, just the overly romanticized modern rewriting their society. Personally I think this silly oversimplification of a complex heritage is insulting. There is a lot of good and bad and brutality and wisdom in the history of all people. I can’t imagine getting personal about the actions of my 11000 year old ancestor.

  22. #22 Ed Straker
    May 20, 2010

    “I can’t imagine getting personal about the actions of my 11000 year old ancestor.”

    I’m afraid that the blame game is a big part of it. You see that playing out right now over the oil spill, for instance. People are more interested in ascribing blame, of looking for some target for vengeance, than dealing with the crisis itself. We’ll get a lot more of this later on, like if the oceans really ARE fished to extinction, and the many other key collapse milestones. There will be no end to the fingerpointing.

  23. #23 darwinsdog
    May 20, 2010

    I’m not questioning native american oral history…

    You’re not? So after the Holy People had the stars all laid out in orderly fashion on a blanket, Coyote really did come along and flip the blanket so that the stars ended up in random positions? May as well believe that bats are birds, that rabbits are ruminants, that snakes eat dirt and can talk, as the OT would have it. Mythology may be interesting but it isn’t to be taken unquestioningly.

  24. #24 Claire
    May 20, 2010

    I have more sympathies with Sharon and Eric’s friend since I have read the book 1491 by Charles Mann. It lays out a pretty good case for the existence of people in the Americas for long before the megafauna died out – as long as tens of thousands of years before the megafauna died out. To me the most interesting part of this is, if there were in fact humans who co-existed with large megafauna for as much as 10,000-20,000 years or more (Mann’s book lays out the case for this being a reasonable possibility), knowing how this was done could be quite relevant to our current predicament. If we are humble enough to admit that we need to learn something, that is (and I am not at all convinced of that).

    As for the argument that it couldn’t have been done because people everywhere are pretty much alike, well, people are clever so there is no a priori reason to suppose that somewhere, some group or groups of humans could not have figured out a way to live that preserved the megafauna for tens of thousands of years. Maybe it didn’t last through the changing climate; maybe people ate them then, out of desperation. Or maybe not; maybe humans and megafauna both died out due to inability to adjust. But we can avoid an overly romanticized view of certain groups of humans and still as least keep as a possibility that those groups of humans did figure out how to do something that, so far, we have not – and try to understand how they did it and how that response may have relevance now.

  25. #25 darwinsdog
    May 20, 2010

    The thing is, Claire, that there is no “good case” for human presence in the Americas prior to ~14K yrs bp, and even that was in Alaska & the Yukon. Sure, people like Mann will offer pseudoscience & special pleading in order to make a case for an earlier presence but it’s just a bogus effort designed to sell books to a gullible reading public. Unlike unscrupulous authors, radiometric dating doesn’t lie. The fact of the matter is that when sophisticated big game hunters possessing pit-trap technology and armed with the atlatl and fluted lithic points arrived in Beringia and dispersed southward, the Pleistocene American mega-fauna was hammered, with many species extinct within a mere 2K yrs of human advent. So if the evidence supported prolonged human coexistence with the American mega-fauna then you might be correct that this coexistence has relevance to the current situation. Since the evidence does not support such coexistence, despite some opportunistic author’s claim otherwise, your point is moot.

  26. #26 Jason
    May 20, 2010

    Darwinsdog, don’t be an idiot. I never said I believed in native american mythology. I meant, as should have been obvious since I was directly referencing Greenpa’s comment, that I didn’t question the existence of the well-documented multi-generational oral histories Greenpa referred to.

  27. #27 darwinsdog
    May 21, 2010

    Darwinsdog, don’t be an idiot.

    Sorry, can’t help it..

  28. #28 Kiashu
    May 22, 2010

    “The team’s results show that continents which suffered larger climate change impacts suffered larger extinctions of small mammals and viceversa, further strengthening the idea that climate change was a key factor in controlling past extinctions on a global scale.”

    It might also be that climate change caused a change in the foods available, so that certain animals were more likely to be eaten. I mean, if the ice comes and there’s no more nuts and roots to munch on, that mammoth starts looking tasty.

    This is a significant risk of peak fossil fuels and climate change, that resource depletion will become worse. If there’s no gas to burn to cook with, people will cut down trees, without trees lots of animals can’t live.

    Thus, human action can be spurred by climate change.

    But really it doesn’t matter what we did or didn’t do in the past. We can always come up with new things. Once women regularly died in childbirth across the world, now it’s rare in a third of the world. If we can come up with new ways in health and the rest, we can certainly come up with new ways of living without gutting the Earth.

  29. #29 Tim Morris
    December 6, 2010

    Tim Flannery in his book “the future eaters” stated that by the time many native cultures had started sustanability measures during the later parts of the last ice age, the larger species that, understandably, had caused them so much competitive trouble, were on their way out for both reasons anyhow.

  30. #30 Anthony Catterton
    October 26, 2011

    This was way too long old man who wrote this!!! I need to write an essay on glyptodons and ou give me this long story about what happened when you were a teacher? Come on dude.

  31. #31 jeiker
    May 23, 2012

    You have brought up a very superb points , thanks for the post.

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